A consensus exists among government agencies, research institutions, industry, grower organizations, and the general public that regularly scheduled applications of broad-spectrum pesticides should be reduced, as these pesticides give rise to a number of economical, environmental, and social issues (e.g., overuse of pesticides, pesticide resistance, toxicity to natural enemies, worker safety, food residues, etcetera). Developing IPM programs based on ecologically sound technologies offers a unique opportunity toward meeting this and other needs.
Monitoring insect populations is an important component in any ecologically sound IPM program. For example, if a grower underestimates an insect population to be below a treatment threshold, the grower may not apply pesticide even though there are enough insects to cause serious fruit damage. On the other hand, if the grower overestimates the insect population to be above the treatment threshold when it is actually below the treatment threshold, the grower may waste money and resources by applying unnecessary pesticides.
In the tree fruit industry, the most economically significant insects are moths, including, but not limited to, codling moths (Cydia pomonella), Oriental fruit moths (Grapholita molesta), and leafrollers (Archips argyrospila and Choristoneura rosaceana). In the stored product industry, moths and beetles are the two major pests, including, but not limited to, Indianmeal moths (Plodia interpunctella), Mediterranean flour moths (Ephestia kuehniella), cigarette beetles (Lasioderma serricorne), and warehouse beetles (Trogoderma variabile). For each of these insects, artificial lures have been developed based on the specific sex pheromone that the female of each species uses to attract males for mating. During the last three to four decades, the capture of male moths in pheromone-baited traps has been the most principled measure utilized to control insect populations and to inform pest management decisions (e.g., when to initiate a pesticide treatment, where and how much pesticide to apply, etcetera). Such techniques have permitted a relatively large decrease in the number of pesticide applications, as described in M. G. Solomon, Integrated Pest Management (1987); O. B. Kovanci et al., Comparison of Mating Disruption with Pesticides for Management of Oriental Fruit Moth (Lepidoptera: Tortricidae) in North Carolina Apple Orchards, J. Econ. Entomology 1248-58 (2005); D. Thomson et al., Ten Years Implementing Codling Moth Mating Disruption in the Orchards of Washington and British Columbia: Starting Right and Managing for Success, IOBC WPRS Bulletin 23-30. (2001); T. Alway, Codling Moth Mating Disruption and Establishing a Pheromone-Based Codling Moth Management Site in the Pacific Northwest, Wash. State Univ. (1998); L. J. Gut et al., Pheromone-Based Management of Codling Moth (Lepidoptera: Tortricidae) in Washington Apple Orchards, J. Agric. Entomology 387-405 (1998); and L. H. Blommers, Integrated Pest Management in European Apple Orchards, 39 Ann. Rev. Entomology 213-41 (1994), the entire disclosures of which are each incorporated by reference herein.
Despite the potential benefit, the labor-intensive activities associated with managing pheromone traps have been a key factor slowing down their widespread adoption. It is typically recommended that pheromone traps be distributed at densities of one trap per hectare (i.e., about 100 m apart) for tree fruit pests and one trap per 100 m2 (i.e., about 10 m apart) for stored product pests. Additional traps are often needed around the border and other areas susceptible to new pest immigrations. Currently, pheromone traps need to be inspected on a regular basis—typically one to five times per week depending on the time of the season and the pest species. Trap inspection typically consists of (1) locating individual traps, (2) manually counting the number of target pests captured in each trap and writing the number down on a piece of paper, and (3) replacing the sticky bottom in each trap, as insects and other debris cover the sticky bottom. As such, the labor costs associated with pheromone traps can easily become prohibitively expensive (i.e., greater than any savings realized from pesticide reduction). These labor costs have been documented in S. C. Welter, Range of Attraction for Modified Pheromone Ttrap-Lure Combinations for Mating Disruption Orchards, Calif. Pear Advisory Bd. (1997); E. R. Williamson et al., Economics of Employing Pheromones for Mating Disruption of the Codling Moth, Carpocapsa Pomonella, Crop Protection 473-477 (1996); L. H. Blommers (cited above); and P. G. Fenemore et al., Problems of Implementing Improvements in Pest Control: A Case Study of Apples in the UK, Crop Protection 51-70 (1985), the entire disclosures of which are each incorporated by reference herein. Constant monitoring of insect populations thus remains one of the most challenging components of any IPM program.